Highly selective and ultrasensitive detection of Hg(2+) based on fluorescence quenching of Au nanoclusters by Hg(2+)-Au(+) interactions.

A simple label-free method for the detection of Hg(2+) ions with high selectivity and sensitivity has been developed by using fluorescent Au NCs in aqueous media. The sensing mechanism was based on the high-affinity metallophilic Hg(2+)-Au(+) interactions, which effectively quenched the fluorescence of Au NCs.